1. Technical Field
This invention relates generally to semiconductor devices and semiconductor device fabrication, and more particularly to MPS (merged PN/Schottky) devices and fabrication.
2. Discussion of Related Art
B. J. Baliga, The Pinch Rectifier: A Low-Forward-Drop High-Speed Power Diode, IEEE Electron Device Letters, June 1984, pp. 194-196, Vol. 5, Issue 6 describes a Schottky barrier diode with a junction grid placed under and in contact with the Schottky metal. The junction grid pinches off current flow under reverse bias but not under forward bias.
Shang-hui L. Tu & B. Jayant Baliga, Controlling the Characteristics of the MPS Rectifier by Variation of Area of Schottky Region, IEEE Transactions on Electron Devices, July 1993, pp. 1307-1315, Vol. 40, Issue 7 describes varying the characteristics of an MPS diode (such as forward voltage drop, breakdown voltage, leakage current, and reverse recovery time) by varying the ratio of Schottky junction region area to p-n junction region area.
A. Hefner, Jr. & D. Berning, Silicon Carbide Merged PiN Schottky Diode Switching Characteristics and Evaluation for Power Supply Application, Conference Record of the 2000 IEEE Industry Applications Conference, 8-12 Oct. 2000, pp. 2948-2954 describes a 1500 volt, 0.5 amp silicon carbide based MPS diode. The diode is able to operate at higher temperatures than a comparable silicon based MPS diode, and has low on-state voltage drop, low off-state leakage, and fast switching characteristics.
U.S. Pat. No. 6,462,393 describes an MPS diode with an array of buried P+ areas.
U.S. Pat. No. 6,710,419 describes a method of manufacturing an MPS diode with an array of buried P+ areas.
A need remains for an MPS diode having improved Schottky area and reduced resistance.